Common practice to protect cargo stacked on pallets during transit is to position bags filled with moderately compressed air between the rows of pallets. The bags are typically vinyl or reinforced paper.
Because of the large number of bags in use there has been much interest in reducing the cost of the bags and associated equipment and reducing the time and inconvenience required to place and inflate the bags and then deflate and remove the bag after transit is complete. A number of disclosures have appeared to reduce these costs and inconveniences.
For example, U.S. Pat. No. 4,073,389 to Angarola et al discloses a housing engaging a spring loaded plug that permits one way entry of air into the bag. The valve tends to dysfunction and leak with aging of the spring.
U.S. Pat. No. 4,102,364 to Leslie et al discloses a system for rapid pressurizing the air inside the bag from a source of high pressure air.
U.S. Pat. Nos. 4,146,069 and 4,146,070 to Angarola et al discloses another system for rapid filling using a stream of pressurized air to aspirate ambient air into the bag.
U.S. Pat. No. 5,111,838 to Langston discloses a spring loaded valve member movable to open a passage and threaded opening to engage an air hose.
U.S. Pat. No. 5,806,572 discloses an apparatus for inflating a bag to a desired limit.
U.S. Pat. No. 6,053,222 discloses a gun that both inflates the bag when required and accelerates deflation of the bag when required.
None of the several versions of a valve for a dunnage bag described in the cited art prevent leakage especially when the stacks of goods, cushioned by the bags, must remain in storage for a long time. Furthermore, it would be desirable to be able to completely separate the valve from the bag so that, especially if the bag becomes damaged, it would be possible to reuse the valve on another bag.